1. Field of the Invention
The present invention relates in general to turn signal indicators, and more specifically, to deactivation of a turn signal after the occurrence or nonoccurrence of a lane change.
2. Description of the Related Art
A turn signal indicator is utilized for alerting other drivers on a roadway that a lane change or a turn is about to be initiated by a vehicle. When the turn signal indicator is activated, it remains active until the vehicle completes a turn or until a driver manually deactivates the turn signal indicator. When the vehicle completes the turn, deactivation of the turn signal indicator is accomplished by a mechanism associated with a steering column. The mechanism requires that the steering column be rotated passed a certain degree point before deactivation of the turn signal indicator occurs. However, a lane change to an adjacent roadway lane does not usually involve the degree of rotation that would deactivate the turn signal indicator. In many cases, the driver of the vehicle activating the turn signal indicator forgets to deactivate the turn signal indicator after changing lanes. This becomes a concern as other surrounding drivers are uncertain as to the intention of whether a lane change is imminent or not. Certain indicators such as audio or visual awareness signals have been used to alert the driver that the turn signal is active, but audio signals can be drowned out by road or wind noise. Likewise, visual signals located in the display of the dashboard may not be seen by the driver if the driver's attention is focused on the roadway.
Methods used to deactivate the turn signal indicator by estimating whether a lane change has occurred include measuring a predetermined distance traveled by the vehicle after activating the turn signal indicator or measuring the length of time the turn signal has been activated. However, systems such as these only assume that the lane change has been made. There is no verification whether or not the lane change has taken place.
Lane departure or lane tracking systems used primarily in trucking industries to alert drowsy drivers when they are departing from a lane are for detecting a lane departure but these systems are not capable of controlling the deactivation of turn signal indicators; rather, the systems have been used to alert the drowsy driver, usually by an audible signal, that an undesired lane change is occurring. Sensing technology known to detect road position and lane deviation includes sensors using roadway reflective properties, sensors generating image data, accelerometers, and gyroscopes.